D. There are two phosphate ions in a molecule of magnesium phosphate
The work done by Joe is 0 J.
<u>Explanation</u>:
When a force is applied to an object, there will be a movement because of the applied force to a certain distance. This transfer of energy when a force is applied to an object that tends to move the object is known as work done.
The energy is transferred from one state to another and the stored energy is equal to the work done.
W = F . D
where F represents the force in newton,
D represents the distance or displacement of an object.
Force = 0 N, D = 20 cm = 0.20 m
W = 0
0.20 = 0 J.
Hence the work done by Joe is 0 J.
<span>Given:
3,500 kilometers
Find:</span>
Years for two continents to collide = ?
<span>Solution:
We know that </span>typical motions of one plate relative to another
are 1 centimeter per year.
So first, we convert 3,500 km to cm.<span>
</span><span>
</span>
The solution would be like this for this specific problem:
1 km = 100,000 cm
3,500 km x 100,000 = 350,000,000 cm
Since we know that 1 cm = 1 year, then that means
350,000,000 cm is equivalent to 350,000,000 years.
Therefore, it would take 350 million years for two continents
that are 3500 kilometers apart to collide.
<span>
To add, </span>a phenomenon of the plate tectonics of Earth that occurs at
convergent boundaries is called the continental collision.